Hi @rpbrookes, to trace this error, it would be very helpful to get some more information such as: Which image are you trying to load? Is the computer properly connected to the internet? Can you open the URL https://imagej.nih.gov/ij/images/ in a browser on that PC? What version of ImageJ (or FIJI?) do you have installed? What operating system version are you running on? Thanks, Robert

Which version of Fiji did you install? Does is come with bundled Java, if so, which version? You can check that in the status bar of ImageJ/Fiji when it first starts up.